Emergency call systems are known in which a person in distress can get immediate help. Specifically, in such systems, the person presses a button on a pendant which transmits a signal to an alarm in the person's house. The alarm then sends a signal to a central station, and a person at the central station must then dial the telephone numbers from a prescribed list in order to obtain aid for the distressed person.
However, such an arrangement is relatively complicated and costly. Specifically, such arrangement operates in a similar manner to a central burglar or fire alarm in a house, and requires a separate, complicated wiring assembly for the house, at a considerable cost. Also, such a system requires that a central station be provided, and therefore, the subscriber to such a system must pay a monthly fee for such service, adding further to the cost of the system.
Also, a problem with known systems is that if a central station, upon calling a telephone number of attempts, so that the person in distress does not receive aid.
Emergency call systems have therefore been invented which are connected to the telephone line and enable a caller to automatically call a plurality of other parties to leave an emergency message, sometimes, simply by pressing a button.
Examples of such emergency call systems are disclosed in U.S. Pat. Nos. 6,212,260 and 6,614,883, incorporated by reference herein, wherein the emergency call systems include an emergency call unit having a memory for storing telephone numbers to be called and an emergency message, an emergency key, and a microprocessor for controlling storage of the telephone numbers and emergency message in the memory, after the dial tone is obtained, dialing the telephone numbers in sequence upon activation of the emergency key, starting a transmit of the emergency message to the dialed telephone number to automatically advise of an emergency after a predetermined time after the telephone number has been dialed and no busy signal has been detected during a predetermined time period, and restarting the transmit of the emergency message to the dialed telephone number to automatically advise of an emergency after detecting each ring-back from each telephone number.
It is now desirable to provide an emergency call system which has a mode of operation which does not require detection of a dial tone to initiate dialing of the telephone numbers, this mode being addition or alternative to operation of the emergency call system using dial tone detect as disclosed in the '260 and '883 patents.